Friction and Wear Reduction in Copper with a Gradient Nano-grained Surface Layer

Area of Science:

• Materials Science
• Tribology
• Surface Engineering

Background:

• Friction and wear are critical factors affecting material performance and longevity.
• Developing advanced surface structures is key to improving tribological properties.

Purpose of the Study:

• To investigate the friction and wear behavior of gradient nano-grained (GNG) copper surfaces.
• To elucidate the underlying mechanisms responsible for enhanced tribological performance in GNG copper.

Main Methods:

• Fabrication of a gradient nano-grained surface layer on commercial-purity copper.
• Tribological testing to evaluate coefficient of friction and wear loss.
• Microstructural analysis using advanced electron microscopy and stress field modeling.

Main Results:

• GNG copper surfaces showed significantly reduced coefficient of friction and wear loss compared to coarse-grained and conventional nano-grained counterparts.
• A novel mild ploughing mechanism without subsurface damage was identified in GNG copper.
• The GNG structure exhibited an inhomogeneous substructure that accommodated deformation and suppressed strain localization.

Conclusions:

• Gradient nano-graining is an effective strategy for enhancing the friction and wear resistance of copper.
• The superior tribological performance is attributed to the unique microstructural evolution and suppressed strain localization within the GNG layer.
• The findings offer insights into designing advanced materials with improved wear characteristics.